DEV Community: Sameer

Answer:

Sameer — Tue, 11 May 2021 22:56:52 +0000

answer re: What does 256 means for 128 unique characters in ascii table

Jul 20 '16

Basically, we use only 128 total character which is used mostly during program But total number of Character in ASCII table is 256 (0 to 255) 0 to 31(total 32 character ) is called as ASCII control characters (character code 0-31). 32 to 127 character is called as ASCII printable…

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Answer:

Sameer — Thu, 15 Apr 2021 23:42:56 +0000

answer re: Is Network.Socket programming in Haskell "Concurrently, Asynchronously, Parallel, Non-Blocking" using forkIO

Sep 20 '18

Note that forkIO spawns a green thread, not an O/S thread, so if you spawn 1000 forkIO threads to handle simultaneous requests, that does not correspond to 1000 separate O/S (or "CPU") threads.

Anyway, yes, the RTS handles multiple blocking read/write calls concurrently without tying up O/S threads. In fact…

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Answer:

Sameer — Wed, 14 Apr 2021 03:51:41 +0000

answer re: Why does FParsec not consume characters parsing a list separator?

Jun 1 '18

This happens, because manySatisfy matches zero or more characters that satisfy the given predicate, the key word being "zero". This means that, at the very end of input, isSeparator actually succeeds, even though it doesn't consume any characters. And since isSeparator succeeds, sepBy is expecting to find another instance of…

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Answer:

Sameer — Tue, 13 Apr 2021 21:28:19 +0000

answer re: Regular Expression Vs. String Parsing

Aug 10 '12

It depends on how complex the language you're dealing with is.

Splitting

This is great when it works, but only works when there are no escaping conventions. It does not work for CSV for example because commas inside quoted strings are not proper split points.

foo,bar,baz

can be split…

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Answer:

Sameer — Fri, 09 Apr 2021 17:19:48 +0000

answer re: What is the difference between Type and Class?

Apr 20 '09

127

The following answer is from Gof book (Design Patterns)

An object's class defines how the object is implemented .The class defines object's internal state and the implementation of its operations.

In contrast, an object's type only refers to its interface - a set of requests to which it…

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Answer:

Sameer — Wed, 03 Mar 2021 21:40:10 +0000

answer re: What is meant by "Capture-avoiding substitutions"?

Jul 4 '12

Normally, the specific variable names that we chose in the lambda calculus are meaningless - a function of x is the same thing as a function of a or b or c. In other words:

(λx.(λy.yx)) is equivalent to (λa.(λb.ba)) - renaming x to a and y to b…

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Answer:

Sameer — Sat, 13 Feb 2021 04:05:37 +0000

answer re: What is a higher kinded type in Scala?

Jun 6 '11

I would say: A higher kinded type abstracts over a type constructor. E.g. consider

trait Functor [F[_]] {
   def map[A,B] (fn: A=>B)(fa: F[A]): F[B]
}

Here Functor is a "higher kinded type" (as used in the "Generics of a Higher Kind" paper). It is not a concrete ("first-order") type…

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Answer:

Sameer — Fri, 12 Feb 2021 18:36:04 +0000

answer re: Equivalence Class Testing vs. Boundary Value Testing

Dec 23 '09

The Equivalence testing needs to be supplemented with the Boundary value testing.

For example for equivalent testing of a function that takes values between 1 and 12
(say months of a year) the partitions would be:

values less than 1 (0,-1,-2), invalid partition

values between 1-12, valid partition

values greater…

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Answer: Haskell type substitution

Sameer — Sat, 06 Feb 2021 19:11:34 +0000

answer re: Haskell type substitution

Mar 8 '19

If I have f :: Num a => a this means that I can use f wherever I need any numeric type. So, all of f :: Int, f :: Double must type check.

In your case, we can't have 1.0 :: Int for the same reason we can't…

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Answer:

Sameer — Sat, 06 Feb 2021 07:35:38 +0000

answer re: What is a higher kinded type in Scala?

Jun 6 '11

The kind of ordinary types like Int and Char, whose instances are values, is *. The kind of unary type constructors like Maybe is * -> *; binary type constructors like Either have (curried) kind * -> * -> *, and so on. You…

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Answer:

Sameer — Tue, 02 Feb 2021 03:56:05 +0000

answer re: How to write less boilerplate in a expression evaluator written with recursion-schemes

Feb 9 '18

Alternatively you could refactor your language to have binary operations on one hand and unary ones on the other. You'd write:

data BinOp = PlusOp | MultOp deriving (Show, Eq)
data UnOp  = ConstOp deriving (Show, Eq)

data Expr  = Bin BinOp Expr  Expr
           | Un  UnOp  Expr
         deriving (Show,

…

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Answer:

Sameer — Sun, 31 Jan 2021 03:09:06 +0000

answer re: Are the xor and not gates logically complete

Apr 28 '12

NOR and NAND are the only functionally complete singleton gate sets. Hence, XOR is not functionally complete on its own (or together with NOT, since as point out above NOT can be created using XOR).

XOR can be complemented to a two-element functionally complete gate sets. One should add (left…

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